Minute structures for producing colors and spinnerets for manufacturing same

ABSTRACT

A minute structure for producing a color comprises a first coloring part for producing a color with first wavelengths in the visible light area by physical actions such as reflection and Interference. The first coloring part includes lamellas disposed in layers at predetermined intervals. A second coloring part is disposed adjacent to the first coloring part for absorbing a part of light with second wavelengths in the visible light area and reflecting the rest of light. The second coloring part contains a coloring matter.

BACKGROUND OF THE INVENTION

The present invention relates to minute structures for producing colorswhich are applied to fabrics, coating fibers and chips, etc. The presentinvention also relates to spinnerets for manufacturing the minutestructures.

Conventionally, a method of adopting inorganic or organic dyes andpigments or scattering bright members such as aluminum and mica flakesin paints has been in general use for providing various fibers and carcoatings with desired colors or improved visual quality.

Recently, with an user's tendency to a high fabric quality, etc., thereare increasing demands on graceful and quality minute structures whichhave tones varying with a change in the angle of view and having highchromas. Some minute structures are developed and proposed to satisfythe above demands. One is such as to produce a color by reflection,interference, diffraction or scattering of light without using coloringmatters such as dyes and pigments. The other is such as to produce abrighter color by combining the above optical action and the dyes andpigments.

JP 43-14185 and JP-A 1-139803 disclose coated-type composite fibers withiridescence which are made of two or more resins having differentrefractive indexes.

A journal of the Textile Machinery Society of Japan (Vol. 42, No. 2, pp.55-62, published in 1989 and Vol. 42, No. 10, pp. 60-68, published in1989) describes laminated photo-controllable polymer films for producingcolors by optical interference, wherein a film with anisotropicmolecular orientation is interposed between two polarizing films.

JP-A 59-228042, JP-B2 60-24847 and JP-B2 63-64535 disclose fabrics withiridescence conceived, e.g. from a South American morpho-butterfly whichis well-known by its bright tone varying with a change in the angle ofview.

JP-A 62-170510 and JP-A 63-120642 disclose fibers and sheetlike articleswhich produce interference colors due to recesses with a predeterminedwidth formed on the surface thereof, respectively. Each documentdescribes that formed objects are fast and permanent in color due to nouse of dyes and pigments.

The minute structures as disclosed in JP 43-14185 and JP-A 1-139803 havean advantage of producing colors irrespective of the incident directionof light, but are imperfect in view of tone brightness and visualquality due to the fact that the optical thickness (geometricalthickness of a covering layer x refractive index thereof is not alwaysconstant when viewed from the incident direction of light.

The minute structure as described in the journal of the TextileMachinery Society of Japan is difficult to be formed in fine fibers andminute chips or pieces, and are still imperfect in view of tonebrightness.

The minute structures as disclosed in JP-A 59-228042, JP-B2 60-24847,JP-B2 63-64535, JP-A 62-170510, and JP-A 63-120642 are difficult to givedesired coloring function due to no precise teachings of the dimensionthereof.

For solving such inconveniences, U.S. Pat. No. 5,407,738 and U.S. Pat.No. 5,472,798 propose new minute structures, with concrete dimension,for producing colors which have bright tones varying with a change withthe angle of view by reflection and interference of light, and no changewith time. The teachings of U.S. Pat. No. 5,407,738 and U.S. Pat. No.5,472,798 are hereby incorporated by reference.

The minute structures as disclosed in U.S. Pat. No. 5,407,738, whichproduce colors by reflection and interference of light, i.e. whensatisfying the interference condition with regard to the refractiveindex and thickness of two component substance layers, are inferior indiversity than the conventional minute structures comprising generallycoloring matters which can produce various colors by mixing coloringmatters of different kinds.

Moreover, the above minute structures, which are made of materialshaving optical penetrability, may be out of the coloring condition whencontacting a transparent substance layer, not determined. That is, whenan environment of the minute structures is determined to be an airlayer, the phenomenon occurs that the above minute structures giveexcellent coloring function in the air layer, but do not give sufficientcoloring function in an environment with no air layer.

By way of example, when clothes made of fibers of minute structure arewet with oil (refractive index n=1.34 to 1.54) or water (refractiveindex n=1.33), or put in a solvent, the clothes have a substance layerwith different refractive index formed on the fiber surface, etc.,resulting in no production of desired colors, and occasionally, anoccurrence of see-through.

Therefore, an object of the present invention is to provide minutestructures of high quality which produce, by reflection and interferenceof light, colors with various bright and clear tones and without anypossible occurrence of see-through.

Another object of the present invention is to provide spinnerets formanufacturing the above minute structures.

SUMMARY OF THE INVENTION

According to one aspect of the present invention, there is provided aminute structure for producing a color, comprising:

at least one first part, said first part producing a first color withfirst wavelengths in a visible light area by physical actions, saidfirst part including lamellas disposed in layers at predeterminedintervals; and

a second part disposed adjacent to said first part, said second partabsorbing a part of light with second wavelengths in said visible lightarea and reflecting the rest of light, said second part containing acoloring matter.

Another aspect of the present invention lies in providing a minutestructure for producing a color, comprising:

first parts, each first part producing a first color with firstwavelengths in a visible light area by physical actions, each first partincluding lamellas disposed in layers at predetermined intervals; and

a second part disposed adjacent to said first parts, said second partabsorbing a part of light with second wavelengths in said visible lightarea and reflecting the rest of light, said second part containing acoloring matter,

said first parts being radially disposed around said second part.

Still another aspect of the present invention lies in providing aspinneret for manufacturing an island-in-a-sea type filament out offirst and second island-portion polymers and a sea-portion polymer,comprising:

a partition, said partition including at least one first opening forshaping the first island-portion polymer and a second opening disposedadjacent to said first opening for shaping the second island-portionpolymer, said first opening including first slits disposed in layers;and

passage means arranged at least at a periphery of said first opening forguiding the sea-portion polymer.

Still another aspect of the present invention lies in providing aspinneret for manufacturing an island-in-a-sea type filament out offirst and second island-portion polymers and a sea-portion polymer,comprising:

a partition, said partition having first openings for shaping the firstisland-portion polymer and a second opening arranged adjacent to saidfirst opening for shaping the second island-portion polymer, said firstopenings being disposed around said second opening, each of said firstopenings including first slits disposed in layers; and

passage means arranged at least at a periphery of said first openingsfor guiding the sea-portion polymer.

The other aspect of the present invention lies in providing a minutestructure for producing a color, comprising:

means for producing a first color with first wavelengths in a visiblelight area by physical actions, said producing means including lamellasdisposed in layers at predetermined intervals; and

means disposed adjacent to said producing means for absorbing a part oflight with second wavelengths in said visible light area and reflectingthe rest of light, said absorbing means containing a coloring matter.

A further aspect of the present invention lies in providing a spinneretfor manufacturing an island-in-a-sea type filament out of first andsecond island-portion polymers and a sea-portion polymer, comprising:

means for defining passages for the first and second island-portionpolymers, said defining means including at least one first opening forshaping the first island-portion polymer and a second opening disposedadjacent to said first opening for shaping the second island-portionpolymer, said first opening including first slits disposed in layers;and

means arranged at least at a periphery of said first opening for guidingthe sea-portion polymer.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing a first preferred embodiment of aminute structure for producing a color according to the presentinvention;

FIG. 2 is a view similar to FIG. 1, showing a melt spinning device;

FIG. 3A is a bottom view showing a spinneret of the melt spinningdevice;

FIG. 3B is a perspective view showing a polymer extrusion side of thespinneret;

FIG. 3C is a view similar to FIG. 3B, showing a polymer receiving sideof the spinneret;

FIGS. 4A and 4B are graphs illustrating production of a compound color;

FIG. 5 is a diagrammatic view showing twisted yarns using the minutestructure;

FIG. 6 is a view similar to FIG. 5, showing a fabric using the minutestructure;

FIG. 7 is a view similar to FIG. 2, showing a variant of the firstpreferred embodiment;

FIGS. 8A and 8B are views similar to FIG. 7, showing another variant ofthe first preferred embodiment;

FIGS. 9A and 9B are views similar to FIG. 8B, showing the other variantof the first preferred embodiment;

FIG. 10 is a view similar to FIG. 9B, showing a second preferredembodiment of the present invention;

FIG. 11 is a view similar to FIG. 10, showing a variant of the secondpreferred embodiment;

FIGS. 12A and 12B are views similar to FIG. 11, showing another variantof the second preferred embodiment;

FIGS. 13A and 13B are views similar to FIG. 12B, showing the othervariant of the second preferred embodiment;

FIG. 14 is a view similar to FIG. 13B, showing a third preferredembodiment of the present invention;

FIG. 15 is a view similar to FIG. 3B, showing a spinneret of the meltspinning device;

FIG. 16 is a view similar to FIG. 14, showing a filament obtained by themelt spinning device;

FIG. 17 is a view similar to FIG. 16, illustrating the incidentdirection of light upon evaluation of coloring of the minute structure;

FIGS. 18A and 18B are views similar to FIG. 17, showing a variant of thethird preferred embodiment; and

FIG. 19 is a view similar to FIG. 18B, showing a fourth preferredembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings, a description will be made with regard topreferred embodiments of the present invention.

FIGS. 1-6 show a first embodiment of the present invention. Referring toFIG. 1, a minute structure 1 for producing a color comprises a firstcoloring part 10 and a second coloring part 20 having a rectangularsection and one side on which the first coloring part 10 is disposed.

The first coloring part 10, which is formed in a layer structurecomprising alternate laminations of a substance layer with apredetermined refractive index and an air layer, produces a color withwavelength in a visible light area (wavelengths of 380 to 780 nm) byreflection and interference of light resulting therefrom.

A concrete structure of the first coloring part 10 may be similar to astructure as disclosed, e.g. in U.S. Pat. No. 5,407,738. Specifically,the first coloring part 10 comprises lamellas 11 disposed in layers andparallel to a surface of the second coloring part 20 and with apredetermined slit or space 13 between two adjacent lamellas 11, and acore portion 12 extending perpendicularly from the one side of thesecond coloring part 20 to interconnect the lamellas 11. The lamellas 11of the first coloring part 10 have the same length, and a widthsubstantially equal to a width S of the second coloring part 20, so thatan assemblage of the first coloring part 10 and the second coloring part20 has a substantially rectangular section.

A material for forming the first coloring part 10 is preferably athermoplastic polymer in view of its easy forming and material valuessuch as optical penetrability and refractive index which enableeffective occurrence of reflection and interference of light. Examplesof thermoplastic polymers are polypropylene (PP), polyvinylidenefluoride (PVDF), nylon, polyvinyl alcohol, polyethylene terephtalate(PET), polystyrene (PS), polymethyl methacrylate (PMMA), polycarbonate(PC), polyether etherketone, polyparaphenylene terephthalamid,polyphenylene sulfide (PPS), etc. Copolymers and mixed polymers havingtwo or more of the above polymers are also applicable.

The layer structure of the lamellas 11 serves to not only reflectultraviolet ray and infrared ray, but produce a color with wavelength inthe visible light area by reflection and interference of light.Referring to FIG. 1, suppose that the direction of placing the lamellas11 one upon another is a longitudinal direction of a section of thefirst coloring part 10, and the direction perpendicular thereto is across direction thereof. When the width of the core portion 12 in thecross direction is Wa, and the width of the lamellas 11 in the crossdirection is Wb, the first coloring part 10 is constructed to meet thefollowing relationship:

Wb≧3Wa

Moreover, when the thickness of the slit 13 or air layer in thelongitudinal direction is da, and the thickness of each lamella 11 inthe longitudinal direction is db, and the refractive index of a materialfor forming the lamellas 11 is nb, the first coloring part 10 isconstructed to meet the following relationship:

0.02 μm≦da≦0.4 μm

0.02 μm≦db

1.2≦nb≦1.8

and to have a dispersion of the thickness db of each lamella 11 in thelongitudinal direction, i.e. a maximum value of a manufacturing errorwith respect to a reference value of the thickness db, being less than40%. The above relationship meets the fundamental formula of coloring ofa multilayer model comprising two substances or polymers with differentrefractive indexes by reflection and interference of light: λ=2 (n_(a)^(s)d_(a)+n_(b) ^(s)d_(b))wherein λ is a peak wavelength of reflectingspectrum, n_(a), n_(b) are refractive indexes of the two substances, andd_(a), d_(b) are thicknesses thereof (see, e.g. U.S. Pat. No.5,472,798). That is, under such condition, a designed peak wavelengthwhich corresponds to a tone, a greater refractive index whichcorresponds to a tone brightness, etc. can be obtained. It will be thusunderstood that coloring of the first coloring part 10 by reflection andinterference of light provides a brighter tone and a higher visualquality than ordinary coloring resulting from coloring matters.

The second coloring part 20 produces a color resulting from a chromaticcoloring matter. Note that, contrary to so-called black coloring mattershaving absorption in the whole visible light area, the chromaticcoloring matter absorbs a part of light with given wavelengths in thevisible light area, and reflects the rest of light. As for thedefinition of “chromatic color”, see, e.g. Japanese Industrial StandardZ8105 “Terminology for Colors”, which is incorporated herein byreference.

By way of example, when absorbing parts of light with wavelengthscorresponding to both ends of the visible light area, and reflecting therest of light with wavelengths in the vicinity of 550 nm, a green coloris obtained. When absorbing a part of light with wavelengths less than600 nm, and reflecting the rest of light with wavelengths more than 600nm, a red color is obtained. Note that it is unpreferable to adopt darkcoloring matters having lightness generally less than 4, but to adoptcoloring matters having lightness more than 4, practically, more than 6.As for “dark coloring matters”, see Japanese Industrial Standard Z8721“Method of Specifying Colors by Three Attributes”.

The chromatic coloring matter may be either of inorganic and organictypes which produces a desired color. Moreover, practically, thechromatic coloring matter may be a pigment made of a colored powdermaterial which is not soluble in water and most of organic solvents, ora dye made of an organic powder compound which is soluble in water andoil to disperse in single molecules which are combined with molecules offibers, etc. to produce a color.

Examples of applicable inorganic coloring matters or pigments are oxidessuch as iron oxide red (Fe₂0₃), zinc white (ZnO) and chromium oxide(Cr₂0₃), hydroxides such as chrome yellow (PbCr0₄), viridian and aluminawhite, sulfides such as cadmium red (CdS.CdSe) and cadmium yellow (CdS),chromic acids such as chrome yellow and zinc chromate, etc.

Examples of applicable organic coloring matters are various azocompounds, phthalocyanine compounds, condensed polycyclic compounds suchas perylene, quinacridone and thioindigo, pteridine compounds, etc. Aswill be described later, when using a thermoplastic polymer as acomponent material, the chromatic coloring matter is preferably of theorganic type in view of not only dispersiibility and colorability, butspinnability. In this case, one of the organic coloring matters isselected which can fully resist a forming temperature (or decompositiontemperature) of the thermoplastic polymer.

A material for forming the second coloring part 20 is not specifiedparticularly. However, as will be described later, when integrallyforming the minute structure 1, the second coloring part 20 ispreferably made of a thermoplastic polymer in the same way as the firstcoloring part 10, and is manufactured, e.g. according to a compositespinning method. The second coloring part 20 can be obtained by adding aproper amount of one of the above coloring matters to the thermoplasticpolymer. Alternatively, the second coloring part 20 can be obtained byplacing or printing an ink-like coloring matter on the thermoplasticpolymer.

Referring next to FIG. 2, a description will be made with regard to amelt spinning device 100 for manufacturing the minute structure 1.

The melt spinning device 100 comprises a spinneret 120 held between afirst block 110 and a second block 130. Supplied independently to thespinneret 120 are a first island-portion polymer A as a material of thefirst coloring part 10, a second island-portion polymer B as a materialof the second coloring part 20, and a sea-portion polymer C as amaterial for surrounding an island portion consisting of the first andsecond coloring parts 10, 20. The three polymers A, B, C are joined toeach other on the extrusion side of the spinneret 120, which is thenreduced in diameter through a funnel-shaped portion 131 of the secondblock 130, and is taken out, as an island-in-a-sea type filament, froman outlet 132 of the melt spinning device 100. This filament is wound ona take-up device, not shown.

The first block 110 is formed with supply passages 111, 112, 113 forindependently leading to the spinneret 120 the two island-portionpolymers island-portion polymers A, B, and the sea-portion polymer C. Inorder to enable simultaneous forming of island-in-a-sea type fibers, thespinneret 120 comprises sets of parallel partitions 121 for controllingislandportion passages as will be described later. The first and secondblock 110, 130 comprise sets of corresponding supply passages 111, 112,113 and funnel-shaped portions 131.

Referring to FIGS. 3A-3C, the spinneret 120 will be described in detail.As best seen in FIGS. 3A and 3B, the spinneret 120 comprises, on theextrusion side thereof facing the second block 130, a partition 121 fordefining two island portions through openings 122A, 122B. The opening122A of the partition 121 through which the first island-portion polymerA passes has first slits 123 arranged parallel to each other, and asecond slit 124 arranged perpendicular thereto for interconnecting thefirst slits 123. The opening 122B of the partition 121 through which thesecond island-portion polymer B passes is shaped to have a rectangularportion arranged parallel to an outer one of the first slits 123. Theopenings 122A, 122B of the partition 121 communicate with each other inthe vicinity of an extrusion side end thereof. The slits 123, 124 areadapted to correspond with the desired configuration of the lamellas,core portion, and rectangular portion of the minute structure to beproduced therewith.

Referring to FIGS. 2 and 3C, the spinneret 120 is formed, on the intakeside thereof facing the first block 110, with polymer receiving portions125, 126 corresponding to the supply passages 111, 112 for the first andsecond island-portion polymers A, B. Each polymer receiving portion 125,126 is shaped like a rectangle to cover an outer periphery of thecorresponding opening 122A, 122B of the partition 121, communicatingwith the corresponding opening 122A, 122B. Moreover, the spinneret 120is formed, on the extrusion side thereof, with a supply passage 128which communicates with intake passages 127 corresponding to the supplypassage 113 for the sea-portion polymer C.

Referring to FIG. 2, the second block 130 comprises a funnelshapedportion 131 having outlet 132 with small diameter with respect to theshape of the openings 122A, 122B of the partition 121. The diameter ofan inlet of the funnel-shaped portion 131 is determined to cover thepartition 121, and communicate with the supply passage 128 at least atthe periphery of the opening 122A through which the first island-portionpolymer A is introduced.

The second island-portion polymer B has a coloring matter added. Thefirst island-portion polymer A proceeds from the supply passage 111 ofthe first block 110 to the polymer receiving portion 125 of thespinneret 120, then to the opening 122A with layer portion 123 of thepartition 121. The second island-portion polymer B proceeds from thesupply passage 112 of the first block 110 to the polymer receivingportion 126, then to the opening 122B with rectangular portion of thepartition 121. On the other hand, the sea-portion polymer C proceedsfrom the supply passage 113 of the first block 110 to the intakepassages 127 of the spinneret 120, then to the supply passage 128thereof.

The first island-portion polymer A extruded from the opening 122A formlamellas 11 interconnected by the core portion 12, whereas the secondisland-portion polymer B extruded from the opening 122B form rectangularportion or second coloring part 20 connected to the core portion 12. Thesea-portion polymer C extruded from the supply passage 128 surrounds thelamellas 11 and rectangular portion to form a circular sectioncomposite. The circular section composite enters the funnel-shapedportion 131 of the second block 130 to undergo a diameter reduction withthe sectional shape kept in a similar figure, which is taken out, as anisland-in-a-sea type filament, from the outlet 132 of the melt spinningdevice 100.

The sea-portion polymer C is dissolved by a solvent for its removal fromthe island-in-a-sea type filament, obtaining the fiber-like minutestructure 1 consisting of the first coloring part 10 of the firstisland-portion polymer A and the second coloring part 20 of the secondisland-portion polymer B only.

The operation of the first embodiment will be described. In the statethat an air layer is placed around the first coloring part 10, lightincident on the first coloring part 10 produces a color with wavelengthdetermined in accordance with the coloring dimension or interferencecondition. If reflection on the first coloring part 10 is a totalreflection, light does not reach the second coloring part 20, so thatonly the first coloring part 10 is active in coloring, producing abright tone and a characteristic visual quality.

On the other hand, if reflection on the first coloring part 10 is not atotal reflection, but, e.g. approximately 50% in reflectivity, a part ofthe rest of light forms stray light such as scattered light, and anotherpart of the rest of light penetrates the first coloring part 10, andreaches the second coloring part 20 for reflection and emission withwavelengths proper to a chromatic coloring matter thereof. Thus,viewer's eyes perceive a “compound color” of a color derived from thefirst coloring part 10 and a color derived form the second coloring part20. This “compound color” is due to synergistic effect of coloring ofthe first coloring part 10 based on interference of light and that ofthe second coloring part 20, having a bright and deep tone, and acharacteristic visual quality which cannot be obtained by so-calledordinary colors resulting from coloring matters.

Specifically, when the wavelengths or reflection spectrum of lightemitting from the first coloring part 10 correspond to those of lightemitting from the second coloring part 20, an extremely bright and deeptone is obtained due to synegistic effect of the two. Moreover, when thewavelengths or reflection spectrum of light emitting from the firstcoloring part 10 do not correspond to those of light emitting from thesecond coloring part 20, a compound color is obtained which cannot berealized by the first coloring part 10 only. Even if the first coloringpart 10 produces no color due to some change in conditions, the secondcoloring part 20 produces a color, preventing total colorlessness.

Thus, individual control of colors of the first and second coloringparts 10, 20 enables production of various colors or compound colors. Ifthe first and second coloring parts 10, 20 produce both, e.g. blue, anoutput color is blue. Moreover, referring to FIG. 4A, a synegisticeffect of the two not only produces an effect similar to improvedreflectivity, but contributes to an improvement of deepnesscorresponding approximately to the reflectivity.

Further, if the first coloring part 10 produces green, while the secondcoloring part 20 produces red, an output color or compound color isgenerally yellow. Referring to FIG. 4B, a reflection spectrum shows thatyellow is obtained from production of green and that of red.Furthermore, if the first coloring part 10 produces green, while thesecond coloring part 20 produces blue, an output color or compound coloris generally cyan. These phenomena are explained by the three principlesof colors or additive mixture of colors. In the former case, due to lackof blue of the three principles consisting of red, green and blue,yellow or complementary color of blue is seen. In the latter case, dueto lack of red of the three principles, cyan or complementary color ofred is seen.

On the other hand, coloring of the conventional coloring matters iscarried out in accordance with subtractive mixture of colors. In case ofoil colors or watercolors, for example, when mixing yellow and magentaappropriately, red is obtained; when mixing cyan and yellowappropriately, green is obtained; and when mixing yellow, magenta andcyan, black is obtained.

It is understood that the minute structure 1 produces a color inaccordance with additive mixture of colors, and not subtractive mixturethereof.

Note that the first coloring part 10 only needs to produce a color withwavelength in the visible light area by one of the physical actions suchas reflection, interference, diffraction and scattering of light, or acombination of two or more thereof. Also note that light is notspecified particularly, and may be natural light of the sun, moon, etc.,or artificial light of fluorescent, xenon and mercury lamps.

Consideration will be made with regard to the case that a transparentsubstance layer with refractive index different from that of the airlayer is placed around the minute structure 1. In this case, due todivergence of the optical thickness (geometrical thickness of asubstance layer x refractive index thereof) from a set value, the firstcoloring part 10 is out of the interference condition, not onlyproducing no desired color, but allowing most of incident light to reachthe second coloring part 20 according to the condition.

However, when reaching the second coloring part 20, light is reflectedthereby with wavelengths proper to a coloring matter contained therein,which is perceived by viewer's eyes as a color proper to a chromaticcoloring matter. Therefore, even when contacting a transparent substancewith different refractive index, the minute structure 1 has nosee-through due to existence of the second coloring part 20.

Note that a maximum reflection peak value or reflectivity R of thereflection spectrum of the second coloring part 200 is more than 40%,preferably, more than 60% in view of color perceptibility of viewer'seyes. This corresponds approximately to the lightness more than 4 asdescribed above. Thus, the amount of chromatic coloring matter containedin the second coloring part 20 is adjusted so that the reflectivity ormaximum reflection peak value R of the second coloring part 20 is morethan 40%. In such a way, even when contacting a transparent substancewith different refractive index, the minute structure 1 has nosee-through due to existence of the second coloring part 20.

According to its application, etc., the minute structure 1 may have asea-portion polymer C positively left without being removed from anisland-in-a-sea type filament manufactured by the melt spinning device100.

An example of manufacturing the minute structure 1 will be described.The following materials are prepared: pellets of polyethyleneterephtalate (PET; refractive index n=1.56) for the first coloring part10, pellets of polyethylene terephtalate containing as a chromaticcoloring matter copper phthalocyanine (blue) of an organic coloringmatter for the second coloring part 20, and pellets of polystyrene (PS)for the sea-portion material for holding the first and second coloringparts 10, 20. The melt spinning device 100 is used for spinning.Spinning is carried out at a spinning temperature of 280° C. and awinding speed of 6,000 m/min. Then, the sea-portion polymer C is removedfrom an island-in-a-sea type filament as obtained by a solvent of methylethyl ketone (MEK), obtaining the minute structure 1 with sectionalshape as shown in FIG. 1. The thicknesses of a PET layer and air layerof the minute structure 1 are 0.08 μm and 0.16 μm, respectively. Thetotal number of layers is 15 (PET: 8; air: 7).

A color of the minute structure 1 is evaluated in the air and the water.Upon evaluation in the air, the minute structure 1 is disposed as shownin FIG. 1 with respect to light, a reflection spectrum of which ismeasured at an incident angle of 0° and a receiving angle of 0° by amicrospectrophotometer of Model U-6000 manufactured by Hitachi, Co.,Ltd. Upon evaluation in the water, the coloring condition of the minutestructure 1 is observed visually.

The results of evaluation are as follows. In the air, with thereflectivity of 90%, the reflection spectrum is obtained having a peakat wavelength of 0.48 μm, producing deep blue. The tone and deepness ofthis blue is clearly different from those of blue coloring by reflectionand interference of light only, having a high visual quality. In thewater, the minute structure 1 also produces blue with no occurrence ofsee-through.

In such a way, according to the first embodiment, the minute structure 1produces a color having various bright, clear and deep tones, and acharacteristic visual quality with no occurrence of see-through whencontacting a transparent substance with different refractive index.

Note that the shape and size of the second coloring part 20 are notspecified particularly, and may be selected optionally without loweringan effect of the first coloring part 10. Likewise, the size and numberof the first coloring part 10 may be determined appropriately. Also notethat, when the minute structure 1 serves as a fabric and a brightmember, the flatness (transverse length/longitudinal length) of theminute structure 1 is preferably more than 3 so that the first coloringpart 10 is disposed in the incident direction of light as stably aspossible.

The minute structure 1 can be used to form a twisted yarn or fabric.Specifically, two or more minute structures 1 as single yarns aretwisted to form a twisted yarn. Referring to FIG. 5, twisted yarns 7A,7B are obtained by carrying out S twist of two minute structures 1 and Ztwist thereof, respectively. A pitch of the minute structures 1 whenforming a twisted yarn and a manner of twisting such as S twist or Ztwist are determined appropriately in accordance with the size and shapeof the minute structure 1. Note that two or more first coloring parts 10and known structures or ordinary single yarns may be twisted to obtain atwisted yarn.

In order to obtain a bright tone and a characteristic visual quality ofthe minute structure 1, the first coloring part 10 should be arranged inthe incident direction of light. With such twisted yarn of the minutestructures 1, even if a plane of incidence having the first coloringpart 10 is disposed only one side of the second coloring part 20, thisplane surely faces on the side of light at predetermined intervals.Thus, with increased frequency of facing in the incident direction oflight, a twisted yarn of the minute structures 1 produces the above toneand visual quality.

Referring to FIG. 6, a fabric 8 such as plain weave can be formed out ofa twisted yarn of the minute structures 1. The fabric 8 formed out ofthe twisted yarns 7A, 7B produces a bright, clear and deep tone, and acharacteristic visual quality, and is excellent in practical use due topossible maintaining of its effect even when contacting or being wetwith a substance with different refractive index such as a solvent, oiland water.

FIG. 7 shows a variant of the first embodiment. The structure of thisvariant is substantially the same as that of the first embodiment ofFIG. 1. In this variant, three first coloring parts 10 a are connectedto a second coloring part 20 a. In the same way as the first coloringpart 10, each first coloring part 10 a comprises lamellas 11 a disposedin layers, and a core portion 12 a extending perpendicularly through thelamellas 11 a and having an end connected to the one side of the secondcoloring part 20 a. According to this variant, an arrangement of aplurality of first coloring parts 10 a contributes to increased densityof portions for carrying out reflection and interference of light,obtaining a deeper tone and a higher visual quality.

FIGS. 8A and 8B show another variant of the first embodiment. Referringto FIG. 8A, a first coloring part 10 b made of a thermoplastic polymerwith a predetermined refractive index comprises two parallel lamellas14, 15, and two connections 16 for interconnecting the lamellas 14, 15to form a box-like structure. The lamella 14 is provided with aprotrusion 17 which outwardly perpendicularly protrudes from a centerportion thereof. Each connection 16 is disposed inwardly from an end ofthe lamellas 14, 15 by a predetermined amount. The first coloring part10 b is connected to a second coloring part 20 b through the lamella 15joined to the entirety of one side of the second coloring part 20 b.

According to this variant, though simple in sectional shape, the firstcoloring part 10 b for producing a color resulting from its layerstructure can produce the same effect as those of FIGS. 1 and 7 throughinteraction with the second coloring part 20 b for producing a colorresulting from a chromatic coloring matter. Referring to FIG. 8B, anarrangement of a plurality of first coloring parts 10 b on the secondcoloring part 20 b contributes to a further increase in coloring effect.

FIGS. 9A and 9B show the other variant of the first embodiment.Referring to FIG. 9A, two first coloring parts 10 are disposed on bothsides of the second coloring part 20, each part being the same as acorresponding part of FIG. 1. Referring to FIG. 9B, two sets of threefirst coloring parts 10 a are disposed on both sides of the secondcoloring part 20 a, each part being the same as a corresponding part ofFIG. 7. According to this variant, a light active side of this minutestructure is not only one side thereof, so that a twisted yarn of thisminute structure always ensures a deep tone and a high visual quality byreflection and interference of light regardless of the angle of view.

The above variants can be formed by changing the shape of the openings122A, 122B of the partition 121 of the melt spinning device 120 as shownin FIGS. 3A-3C.

FIG. 10 shows a second embodiment of the present invention. A minutestructure 2 for producing a color comprises a first coloring part 30,and a second coloring part 40 defined by an arc surface and a flatsurface on which the first coloring part 30 is disposed. The firstcoloring part 30 is formed in a layer structure comprising alternatelaminations of substance layers 31, 32 with predetermined refractiveindexes. A concrete structure of the first coloring part 30 may besimilar to a structure as disclosed, e.g. in U.S. Pat. No. 5,472,798.Specifically, when the refractive index of the substance layer 31 is na,and the refractive index of the substance layer 32 is nb, the firstcoloring part 30 is constructed to meet the following relationship:

1.3≦na

1.1≦nb/na≦1.4

The substance layers 31, 32 are made of preferably a thermoplasticpolymer in the same way as in the first embodiment. Moreover, the secondcoloring part 40 contains a chromatic coloring matter in the same way asthe second coloring part 20 in the first embodiment. The first coloringpart 30 as formed in a layer structure has an arc surface which iscontinuous with the arc surface of the second coloring part 40, forminga circular section as a whole. Thus, the minute structure 2 produces acolor with wavelength in the visible light area by reflection andinterference of light based on lamination of the substance layers 31, 32with different refractive indexes.

An example of manufacturing the minute structure 2 will be described.The following materials are prepared: pellets of poly vinylidenefluoride (PVDF; refractive index n=1.41) and polystyrene (PS; refractiveindex n=1.60) for the first coloring part 30, and pellets of polystyrenecontaining as a chromatic coloring matter an organic coloring matter orlake red C (red) for the second coloring part 40.

Used for spinning is a melt spinning device with a spinneret forenabling a diameter reduction of the above three melt polymers whichjoin each other therein. Spinning is carried out at a spinningtemperature of 200° C. and a winding speed of 5,000 m/min, obtaining thefiber-like minute structure 2 with sectional shape as shown in FIG. 10.The thicknesses of a PVDF layer and PS layer of the minute structure 2are 0.08 μm and 0.09 μm, respectively. The total number of layers is 41(PVDF:21; PS : 20).

This melt spinning device, not shown, only needs a spinneret havingslits for PVDF and PS alternately arranged and a partly arc-shapedopening which correspond to the openings 122A, 122B for the first andsecond island-portion polymers A, B of the spinneret 120 of the meltspinning device 100 as described in connection with the firstembodiment, and which have a periphery shaped like a circle. This meltspinning device needs no system for the sea-portion polymer C.

A color of the minute structure 2 is evaluated in the air and the water.Upon evaluation in the air, the minute structure 2 is disposed as shownin FIG. 10 with respect to light, a reflection spectrum of which ismeasured at an incident angle of 0° and a receiving angle of 0° by amicrospectrophotometer of Model U-6000 manufactured by Hitachi, Co.,Ltd. Upon evaluation in the water, the coloring condition of the minutestructure 2 is observed visually.

The results of evaluation are as follows. In the air, with thereflectivity of 70%, yellow with deepness is observed which is acompound color of a color (green; dominant wavelength λ=0.52 μm) derivedfrom the first coloring part 30 and a color (red; dominant wavelengthλ=0.65 μm) derived from the second coloring part 40. In the water, theminute structure 2 produces red with no occurrence of see-through.

FIG. 11 shows a variant of the second embodiment. In this variant, afirst coloring part 30 a formed in a layer structure is disposed on asecond coloring part 40 a to form an elliptical or oval section as awhole. According to this variant, the width of the first coloring part30 a is increased to enlarge the area of the layer structure forcarrying out reflection and interference of light, resulting in anadvantage of further improved depth of the color.

FIGS. 12A and 12B show another variant of the second embodiment. In thisvariant, a first coloring part 30 b, 30 c includes a latticed portion35, 35 a made of a material with a first refractive index and havingslits 36 filled with a material 37 with a second refractive index. Asecond coloring part 40 b, 40 c is connected to the first coloring part30 b, 30 c. Specifically, referring to FIG. 12A, the first coloring part30 b includes latticed portion 35 having a rectangular external form.The plate-like second coloring part 40 b is connected to the entirety ofa long side of the first coloring part 30 b which is parallel to thelongitudinal direction of the slits 36, forming a rectangular section asa whole. The latticed portion 35 and the slits 36 filled with thematerial 37 form lamellas, respectively.

Referring to FIG. 12B, the first coloring part 30 c includes latticedportion 35 a having an elliptical or oval section. The slits 36 arearranged to have the longitudinal direction corresponding to thedirection of a major axis of the ellipse. The arc second coloring part40 c is connected to a side of the first coloring part 30 c in thedirection of the major axis of the ellipse. According to this variant,forming of a plurality of layer structures contributes to achievement ofa deep tone and a high visual quality.

FIGS. 13A and 13B show the other variant of the second embodiment.Referring to FIG. 13A, two first coloring parts 30 d comprisingalternate laminations of substance layers 31 a, 32 a with predeterminedrefractive indexes are arranged on both sides of a second coloring part40 d, forming as a whole a circular section with the second coloringpart 40 d disposed substantially in the center thereof. Referring toFIG. 13B, two first coloring parts 30 e are arranged on both sides of asecond coloring part 40 e, forming as a whole an elliptical or ovalsection with the second coloring part 40 e disposed substantially in thecenter thereof in the direction of a minor axis of the ellipse.According to this variant, effective reflection and interference oflight is ensured with respect to light in the direction of two sides ofthe minute structure.

FIGS. 14-17 show a third embodiment of the present invention. In thethird embodiment, for achieving no dependence on the incident directionof light, first coloring parts 50 are radially arranged around a secondcoloring part 60. Specifically, referring to FIG. 14, a minute structure3 for producing a color comprises first coloring parts 50 which areradially equidistantly arranged around the second coloring part 60having a circular section. The first coloring part 50 comprises lamellas51 disposed in layers and with a predetermined slit or space 53 betweentwo adjacent lamellas, and a core portion 52 extending perpendicularlytherethrough and having an end and connected to the second coloring part60.

In the third embodiment, the lamellas 51 interconnected by the coreportion 52 constitute an unit 70 of first coloring part 50. Eight units70 are radially equidistantly arranged around the second coloring part60 having a circular section, and are connected to the second coloringpart 60. With each unit 70 of first coloring part 50, the length of thelamellas 51 is gradually increased from the lamella 51 a disposed thenearest to the second coloring part 60 to the lamella 51 b disposed themost distant therefrom. A material of the first coloring part 50 is athermoplastic polymer in the same way as the first coloring part 10 inthe first embodiment. Moreover, a material of the second coloring part60 is the same as that of the second coloring part 20 in the firstembodiment.

Note that a maximum reflection peak value or reflectivity R of thereflection spectrum of the second coloring part 60 is more than 40%,preferably, more than 60% in view of color perceptibility of viewer'seyes. This corresponds approximately to the lightness more than 4 asdescribed above. Thus, the amount of chromatic coloring matter containedin the second coloring part 60 is adjusted so that the reflectivity ormaximum reflection peak value R of the second coloring part 60 is morethan 40%.

The minute structure 3 can be manufactured by a spinneret 220 as shownin FIG. 15 in place of the spinneret 120 as shown in FIGS. 3A-3C.Referring to FIG. 15, the spinneret 220, which is circular as viewed ina plan, includes a partition 221 for controlling island-portion passageswhich is formed with openings 222A for the first island-portion polymerA arranged radially around a circular opening 222B for the secondisland-portion polymer B. Each opening 222A includes first slits 223disposed equidistantly, and a second slit 224 extending radially fromthe opening 222B to cross the first slits 223 at right angles. The firstslits 223 are parallel to each other, the length of which is larger asthe distance from the opening 222B is greater. Moreover, the spinneret220 has openings 228 for the sea-portion polymer C formed at theperiphery thereof.

The spinneret 220 includes, on the reverse side thereof, a polymerreceiving portion communicating with the openings 222A, 222B for thefirst and second island-portion polymers A, B in the same way as thespinneret 120 as shown in FIG. 2. The spinneret 220 also includes apolymer receiving portion communicating with the opening 228 for thesea-portion polymer C. The spinneret 220 is arranged in a melt spinningdevice equivalent to the melt spinning device 100 as shown in FIG. 2 toreceive, in the polymer receiving portions, the first and secondisland-portion polymers A, B and the sea-portion polymer C for meltspinning, obtaining an island-in-a-sea type filament 4 as shown in FIG.16 consisting of a first island portion or first coloring part 50, asecond island portion or second coloring part 60, and a sea portion 80surrounding the two. The sea portion 80 is dissolved by a solvent forits removal from the filament 4, obtaining the minute structure 3 asshown in FIG. 14.

According to the third embodiment, even when contacting a transparentsubstance with different refractive index, the minute structure 3 has nosee-through due to existence of the second coloring part 60. Moreover,due to radial arrangement of a plurality of first coloring parts 50, theminute structure 3 produces a bright tone and a characteristic visualquality by reflection and interference of light regardless of theincident direction thereof.

In the third embodiment, the length of the lamellas 51 is graduallyincreased from the lamella 51 a disposed the nearest to the secondcoloring part 60 to the lamella 51 b disposed the most distanttherefrom, resulting in effective reflection and interference of lightincident thereon even with a certain angle, and not perpendicularly.Note that all the lamellas 51 may be the same in length. Also note thatthe number of units 70 of first coloring part 50, eight in the thirdembodiment, is preferably as larger as possible to increase the densitythereof in the section in view of achievement of substantially the samereflection spectrum and reflectivity regardless of the incidentdirection of light.

An example of manufacturing the minute structure 3 will be described.The following materials are prepared: pellets of polyethyleneterephtalate (PET; refractive index n=1.56) for the first coloring part50, pellets of polyethylene terephtalate containing as a chromaticcoloring matter an organic coloring matter or lead phthalocyanine(green) for the second coloring part 60, and pellets of polystyrene (PS)for the seaportion material for holding the first and second coloringparts 50, 60. The melt spinning device with the spinneret 220 as shownin FIG. 15 is used for spinning. Spinning is carried out at a spinningtemperature of 280° C. and a winding speed of 5,000 m/min. Thesea-portion polymer C is removed from an island-in-a-sea type filamentas obtained by a solvent of methyl ethyl ketone (MEK), obtaining theminute structure 3 as shown in FIG. 14. The thicknesses of a PET layerand air layer of the minute structure 50 are 0.08 μm and 0.13 μm,respectively. The total number of layers is 15 (PET: 8; air: 7).

A color of the minute structure 3 is evaluated in the air and the water.Referring to FIG. 17, upon evaluation in the air, the minute structure 3is rotated every 30° up to 180° to vary the incident direction of light,a reflection spectrum of which is measured at an incident angle of 0°and a receiving angle of 0° by a microspectrophotometer of Model U-6000manufactured by Hitachi, Co., Ltd. Upon evaluation in the water, thecoloring condition of the minute structure 3 is observed visually.

The results of evaluation are as follows. In the air, with thereflectivity of approximately 80%, the reflection spectrum is obtainedhaving a peak at wavelength of 0.52 μm at each angle of rotation withina range of 0 to 180° , producing green. The tone and deepness of thisgreen is clearly different from those of green coloring obtained withoutthe second coloring part 60, having a high visual quality. In the water,the minute structure 3 also produces green with no occurrence ofsee-through.

According to the third embodiment, the minute structure 3 produces acolor by reflection and interference of light regardless of the incidentdirection of light with a bright tone and a characteristic visualquality. Moreover, the minute structure 3 is excellent in practical usedue to possible maintaining of its effect even when contacting or beingwet with a substance with different refractive index such as a solvent,oil and water.

FIGS. 18A and 18B shows variants of the third embodiment. Referring toFIG. 18A, the minute structure is the same in shape as that one as shownin FIG. 16, and comprises first and second coloring parts 50, 60, theperiphery of which is filled with a substance 90 with refractive indexn≠1.00 in place of air, forming a fiber-like structure with a circularsection. Referring to FIG. 18B, the minute structure is substantiallythe same as that of the variant as shown in FIG. 18A except no existenceof the core portion 52 of the first coloring part 50. According to thosevariants, also, the minute structure produces a color by reflection andinterference of light regardless of the incident direction of light,having various tones without lowering of brightness, clearness anddeepness. Moreover, the minute structure is excellent in practical usedue to no quality deterioration by the influence of an externalenvironment such as contact with a substance with different refractiveindex.

FIG. 19 shows a fourth embodiment of the present invention. Thestructure of the fourth embodiment is substantially the same as that ofthe third embodiment as shown in FIG. 14 except that a second coloringpart 60 a of a minute structure 5 contains an achromatic coloring matterhaving uniform absorption in the visible light area. Note that the“achromatic coloring matter” is such as to show uniform absorption, i.e.have practically no reflection in the visible light area, includingprincipally black and grey coloring matters. As for the definition of“achromatic color”, see, e.g. Japanese Industrial Standard Z8105“Terminology for Colors”. Examples of achromatic coloring matters arecarbon black (C), iron oxide black (Fe304), zinc white (ZnO), etc. asinorganic coloring matters or pigments, and aniline black, etc. asorganic coloring matters. According to the fourth embodiment, lightincident on the minute structure 5 is subjected to reflection andinterference at units 70 located on the side of a plane of incidence,given wavelengths of which are perceived by viewer's eyes as a color.The units 70 are radially arranged around the second coloring part 60 a,allowing coloring regardless of the incident direction of light.

As described above, in an environment with air layer, the first coloringpart 50 receives light incident on the minute structure 5, producing acolor with wavelength determined in accordance with the interferencecondition. If reflection on the first coloring part 50 is a totalreflection, light does not reach the second coloring part 60 a, so thatonly the first coloring part 50 is active in coloring, producing abright tone and a characteristic visual quality. On the other hand, ifreflection on the first coloring part 50 is not a total reflection, but,e.g. approximately 50% in reflectivity, a part of the rest of light isscattered, and another part of the rest of light penetrates the firstcoloring part 50, and reaches the second coloring part 60 a. When beingreflected thereby, another part of the rest of light operates as straylight with various wavelengths, which may harm a bright color derivedfrom the first coloring part 50. However, according to the fourthembodiment, such stray light and penetrating light are absorbed by thesecond coloring part 60 a containing an achromatic coloring matter, sothat viewer's eyes perceive a bright color derived from the firstcoloring part 50 without being decreased by half.

Likewise, when an periphery of the minute structure 5 is filled with atransparent substance with equivalent refractive index, the firstcoloring part 50 is out of the interference condition, allowing most ofincident light to reach the second coloring part 60 a according to thecondition. However, according to the fourth embodiment, light reachingthe second coloring part 60 a is subjected to absorption in the wholevisible light area by an achromatic coloring matter contained therein,which is perceived by viewer's eyes as black with no occurrence ofsee-through.

An example of manufacturing the minute structure 5 will be described.The following materials are prepared: pellets of polyethyleneterephtalate (PET; refractive index n=1.56) for the first coloring part50, pellets of polyethylene terephtalate containing as an achromaticcoloring matter aniline black (black) of an organic coloring matter forthe second coloring part 60 a, and pellets of polystyrene (PS) for thesea-portion material for holding the first and second coloring parts 50,60 a. The melt spinning device with the spinneret 220 as shown in FIG.15 is used for spinning. Spinning is carried out at a spinningtemperature of 280° C. and a winding speed of 5,000 m/min. Then, thesea-portion polymer C is removed from an island-in-a-sea type filamentas obtained by a solvent of methyl ethyl ketone (MEK), obtaining theminute structure 5 as shown in FIG. 19. The thicknesses of a PET layerand air layer of the minute structure 5 are 0.08 μm and 0.15 μm,respectively. The total number of layers is 15 (PET: 8; air: 7).

A color of the minute structure 5 is evaluated in the air and the water.Upon evaluation in the air, in the same way as in the example in thethird embodiment, the minute structure 5 is rotated every 30° up to 180°to vary the incident direction of light, a reflection spectrum of whichis measured at an incident angle of 0° and a receiving angle of 0° by amicrospectrophotometer of Model U-6000 manufactured by Hitachi, Co.,Ltd. Upon evaluation in the water, the coloring condition of the minutestructure 5 is observed visually.

The results of evaluation are as follows. In the air, with the 5reflectivity of approximately 85%, the reflection spectrum is obtainedhaving a peak at wavelength of 0.48 μm at each angle of rotation withina range of 0 to 180°, producing blue. The tone and deepness of this blueis clearly different from those of blue coloring obtained without thesecond coloring part 60 a, having a high visual quality. In the water,the minute structure 5 produces a dark color or black with no occurrenceof see-through.

Note that, in the same way as the variants of the third embodiment asshown in FIGS. 18A and 18B, the fourth embodiment can be constructedsuch that the periphery of the first and second coloring parts 50, 60 ais filled with a substance with refractive index n≠1.00, or only thelamellas 51 a re disposed radially and in layers in a substance withrefractive index n≠1.00 placed at the periphery of the second coloringpart 60 a.

In the fourth embodiment, the first coloring part 50 which produces acolor resulting from its layer structure may contain an achromaticcoloring matter. However, kinds of pigments and content thereof cancause an increase in absorption in the visible light area, so that lightincident on the minute structure 5 reaches the lower lamellas 51insufficiently. In view of possible deterioration of coloring of thefirst coloring part 50 due to the above fact, the first coloring part 50contains preferably no achromatic coloring matter.

In the above embodiments wherein the second coloring part contains achromatic coloring matter, the first coloring part which produces acolor resulting from its layer structure is constructed to have opticalpenetrability, but not constructed particularly to contain a chromaticcoloring matter. As described above, kinds of pigments and contentthereof can cause an increase in absorption in the visible light area.However, considering attenuation of light incident on the first coloringpart due to the above absorption, the first coloring part can beconstructed to contain a chromatic coloring matter within predeterminedlimits, producing a color in a certain extent.

Moreover, in the above embodiments, the minute structures for producingcolors are formed like a fiber. Alternatively, the minute structures maybe formed like a chip, which are obtained, e.g. by shredding filamentsof the minute structures for addition to coating materials. Moreover,the minute structures described in connection with the variants of thefirst embodiment as shown in FIGS. 7-9B and those of the secondembodiment as shown in FIGS. 11-13B may be spread on two or threedimensional surfaces with the second coloring parts being disposedthereon, which are usable for car coating, etc.

What is claimed is:
 1. A minute structure for producing a color,comprising: at least one first part, said first part producing a firstcolor with first wavelengths in a visible light area by physicalactions, said first part including lamellas disposed in layers atpredetermined intervals; and a second part disposed adjacent to saidfirst part, said second part absorbing a part of light with secondwavelengths in said visible light area and reflecting the rest of light,said second part comprising a coloring compound.
 2. A minute structureas claimed in claim 1, wherein said first part includes a portion forinterconnecting said lamellas.
 3. A minute structure as claimed in claim2, wherein said first part is connected to said second part through saidinterconnecting portion.
 4. A minute structure as claimed in claim 1,wherein said first part comprises a thermoplastic polymer.
 5. A minutestructure as claimed in claim 1, wherein said first and second parts areformed to have a predetermined shape.
 6. A minute structure as claimedin claim 1, wherein said coloring matter of said second part comprises achromatic coloring compound.
 7. A minute structure as claimed in claim6, wherein said chromatic coloring compound comprises at least oneinorganic or organic chromatic coloring compound.
 8. A minute structureas claimed in claim 7, wherein said inorganic chromatic coloringcompound comprises at least one of: an oxide selected from the groupconsisting of iron oxide red (Fe₂0₃), zinc white (ZnO) and chromiumoxide (Cr₂0₃), hydroxide selected from the group consisting of chromeyellow (PbCr0 ₄), viridian and alumina white, a sulfide selected fromthe group consisting of cadmium red (CdS.CdSe) and cadmium yellow (CdS),or a chromic acid selected from the group consisting of chrome yellowand zinc chromate.
 9. A minute structure as claimed in claim 7, whereinsaid organic chromatic coloring compound comprises at least one of: anazo compound, a phthalocyanine compound, a condensed polycyclic compoundselected from the group consisting of perylene, quinacridone andthioindigo, or a pteridine compound.
 10. A minute structure as claimedin claim 1, wherein said second part is constructed so that a maximumreflection peak value of a visible light reflection spectrum thereof ismore than 40%.
 11. A minute structure as claimed in claim 1, whereinsaid second part is constructed so that a maximum reflection peak valueof a visible light reflection spectrum thereof is more than 60%.
 12. Aminute structure as claimed in claim 1, wherein said first part isconnected to said second part through one of said lamellas.
 13. A minutestructure as claimed in claim 1, wherein an outermost lamella of saidlamellas disposed in layers includes a protrusion.
 14. A minutestructure as claimed in claim 1, wherein said lamellas comprise firstand second lamellas, and wherein said first and second lamellas havedifferent refractive indexes disposed alternately.
 15. A minutestructure as claimed in claim 1, wherein said first part includes aportion surrounding said lamellas, the refractive index of said portionbeing different from that of said lamellas.
 16. A minute structure forproducing a color, comprising: at least one first part, each first partproducing a first color with first wavelengths in visible light by atleast one of reflection, interference, diffraction or light scattering,each first part including lamellas disposed in layers at predeterminedintervals; and a second part disposed adjacent to said first part, saidsecond part absorbing light possessing second wavelengths in saidvisible light and reflecting light not possessing said secondwavelength, said second part comprising a coloring compound, said firstparts being radially disposed around said second part.
 17. A minutestructure as claimed in claim 16, wherein said lamellas of each firstpart have a length increased gradually to an outermost of said lamellasdisposed in layers.
 18. A minute structure as claimed in claim 16,further comprising: a third part surrounding said first and secondparts, said third part having a predetermined refractive index.
 19. Aminute structure as claimed in claim 18, wherein said predeterminedrefractive index of said third part is not 1.00.
 20. A minute structureas claimed in claim 16, wherein said coloring compound of said secondpart comprises an achromatic coloring compound.
 21. A minute structurefor producing a color, comprising: means for producing a first colorwith first wavelengths in a visible light area by physical actions, saidproducing means including lamellas disposed in layers at predeterminedintervals; and means disposed adjacent to said producing means forabsorbing a part of light with second wavelengths in said visible lightarea and reflecting the rest of light, said absorbing means containing acoloring compound.
 22. A minute structure which is capable of producinga compound color comprising: a first coloring part producing a firstcolor, a second part adjacent to said first part and comprising achromatic coloring compound which reflects light at particularwavelengths, said second part being configured such that when said straylight emitted from said first part penetrates said second part, at leasta portion of said stray light is emitted at a wavelength of saidchromatic coloring compound to produce a second color.